Method of and apparatus for cementing wells



2 Sheets-Sheet Harvey s 5mm INVENTOR.

ATTORNEY.

Jan. 5, 151932. H. s. sMn-H METHOD OF AND APPARATUS FOR CEMENTING WELLSFiied sept. 25, 1930 A ..w.. ceo Ill A G9a. ccoo j nooo ,i DIIIIIIII-IIIII Jan. 5, 1932. H. s. SMITH METHOD O F AND APPARATUS FORCEMENTING WELLS Filed Sept. 25, 1930 2 Sheets-Sheet 2 INVENTOR.

A TTORNEY.

Patented Jan. 5, 1932 'HARVEY SVSMITH, OF HOUSTON, TEXAS METHOD OF ANDAPPARATUS FOR CEMENTING WELLS Application led'September 25, 19 30.SerialiNo. 484,297.

This invention relates to methods of and 6 and 7, top and side views-'ofthe plug seat,

apparatus for cementing wells.

A conventional procedure after the drilling of a Well includes loweringa casing into the bore, forcing cement through the lower end of thecasing, permitting the cement to harden about the lower end of thecasing, drilling through the cement, and then lowering a tube, which hasa screen yattached to the end thereof, through the casing and the holein the cement. The oil or other Huid flows through the screen andupwardly in the tubing to the surface of the eaith. The space betweenthe casing and the tubing is sealed by suitable packing means.

This invention has for its general object the provision of a new andimproved method of and apparatus for cementing wells.

In accordance with the present invention, the cement is forced througha` casing and respectively. y

The casing comprises a pipe 1 having spaced and' upwardly directedcement exit openings 2. Y

Belowy said openings is the plug seat 3, which is internally tapered(Figs. 6 and 7). It is screwed into the coupling 4 as indicated at 5(Fig. 3). Theplug 6 is frangible and has a cylindrical portion 7, atapered portion 8, and guide rings 9 and 10v at the extremitiesvof itscylindrical portion (Figs. 4 and 5). Suitable outsi'de packing means 11(Fig. 2) may beprovided to prevent dropping of the cement into the spaceabout the screen 65 made to fill the space between a portion of `thecasing remote from' its lower end, and

the wall of the bore, after which communication between the interior ofthe casing and the space in the bore below the cement may readily beeffected to permit the passage of fluid upwardly through the casing.

More specifically, the present invention provides a casing having acement exit opening therein and a screen attached thereto below theopening, and. removable sealing means between the opening and thescreen, so that cement may be forced downwardly into the casing andthrough the opening therein into the space between the casing and thewall of the bore above the screen; and, after the cement has hardened,the sealing means may be removed to permit the How of oil or other Huidthrough the screen and 'upwardly in the casing.

The preferred embodimentofthe apparatus is illustrated by theaccompanying drawings, of which Fig. 1 is a partly sectional elevationof the apparatus with the sealing plug in place; Fig. 2, a similar viewwith the cement in place, the plug having been drilled out; Fig. 3, adetail sectional view illustrating the drilled' plug seat and the flowtubing; Figs. 4 and 5, detail top and partly sectional side views of theplug, respectively; and Figs.

The screen 12 is below the seat 3 and packing means 11, and below thescreen are the back pressure valves 13. The seat for the upper of thesevalves has an annular groove 14 for the reception of a wash tube. Belowthe back pressure Valves are the upwardlyv4 directed openings 15 and inthe bottom of the apparatus is the opening 16.

The method of cementing the well is as follows:

The casing having been lowered into the bore, fluid may be pumped (byany conventional pump not shown) through the casing, the cement exitopenings 2 and the screen 80 openings, to wash out the cement exitopenings 2 and the screen, and the bore about the same. If the screen isunusually long, a wash tube (not shown) smaller than the ow tube 19, maybe lowered in the casing until its end rests in groove '14 of the backpressure valve seat. Fluid may then be forced by the pump through thewash tube, and it will emerge through the openings 15 and 16.

. The plug 6 is then placed in the casing 90 and pumped down until itreaches the seat 3, when the resistance offered the pump will be muchgreater. The operator can therefore tell when the plug has reached itsdestination by observing the'pump. Cement is then 95 I pumped into thecasing and through the openings 2 into the space between the casing andthe wall 18 of the bore, as indicated by Fig. 2. Then a second plug, notshown', may be lpumped down the casing to follow the' cement. 1.0

When this second plug reaches the first plug 6, practically all of thecement will have een expelled from the casing through the o enings 2;and as the second plug is substantially the same as the first plug, thepassage of fluid through the openings 2 will -be obstructed, and thedriller will therefore be advised by the resistance offered to the pumpwhen the second plug has reached the first plug.

The cement is then held under pressure and permitted to set, and thenany conventional drill (not shown) `may be lowered into the casing andmade to cut away the first and second plugs and a part of seat 3.Compare Figs. 1 and 2. The drill will also cut through any cement leftin the casing 1 so that after the drill is removed, oil or other fluidmay move through the screen 12 upwardly in the casing 1 to the surf-ace.The cement will seal the openings 2 so that fluid cannot escapetherethroug but if desired the openings 2 may be positively cut of bythe use of a flow tube 19 lowered in the casing to -rest upon theremaining portion of the seat 2, as shown by Figs. 2 and 3.

Should it be desired to obtain fluid from a point deeper in the earth, adrill may belowered in the casing through the seat 3, and made to cutaway the back pressure valves 13 and their seats, pass through the lowerend of the apparatus, and penetrate the earth to the desired depth. Thedrill stem may then be removed and a casing smaller but of the same typeas that hereinabove described may be i lowered through the originalcasing into the new bore and cemented in a like manner. The secondcasing may be drilled through, and a third smaller and similar casingemployed,

and so on, to secure fluid from point after point farther away from theearths surface.

I claim:

1 Well cementing apparatus comprising a pipe having a normallyunobstructed ce.

ment exit opening therein', a plug seat below .said opening, .a screenbelow said seat, said ment' exit opening therein, a plug seat below saidopening, a screen below said seat, said seat having an openingcommunicating with said pipe and said screen, a back pressure means andsaid seat, said seat having an opening communicating with said pipe andsaid screen, and a plu movable'downwardly in said pipe into sea ingengagement with said seat to close the opening in said seat.

4. Well cefnenting apparatus comprising a pi e having a normallyunobstructed upwar ly directed cement exit opening therein, a plug seatbelow said opening, a screen below said seat, said seat having adownwardly tapered opening communicating with said pipe and said screen,and a plug movable downwardly in said pipe into sealing engagement withsaid seat to close the opening in said seat.

.5. Well cementing apparatus comprising a pipe having a normallyunobstructed upwardly directedcement exit opening therein, a plug seatbelow said opening, outside packing means below said opening, a screenbelow said packing means and seat, said seat having a downwardly tapered'opening communieating with said pipe and said screen, and a plugmovable downwardly in said pipe into sealing engagement with said seatto close the opening in said seat.

In testimony whereof, I hereunto atx my signature.

HARVEY S. SMITH.

valve below said screen, and a plug movable I downwardly in said pipeinto sealing engagement with said seat to close the opening in saidseat. Y

3. Well cementing apparatusl comprising a pipe having a normallyunobstructed cement exit opening therein, a plug seat below saidopening, outside packing meansbelow said opening, a^screen below saidpacking

